I&M NUMBER: 316-42-10-1 Page: 1 Pre Installation Check to make sure that heater received is the same as that ordered. Elements may come in contact with each other during shipment. Minor adjustments to elements may be required prior to installation to separate them. Extensive bending of elements should be avoided since dielectric strength between coil and sheath may be compromised. Watlow heaters are built to comply with UL, CSA, and CE LVD dielectric requirements, it may be necessary due to atmospheric conditions / humidity, to perform a dielectric test prior to startup. (Refer to megohm test under Installation section) Safety Electric heaters are inherently dangerous!! Care should be taken to read and completely understand the Installation and Maintenance manual before installing and wiring the heater. Any installation and maintenance performed on the heater shall be done by a qualified electrician, in accordance with the "National Electric Code" and other electrical codes as they apply. It is the users responsibility to ensure that the heater being used is properly selected and installed in the application.! The Caution Symbol (exclamation point) alerts you to a "CAUTION", a safety or functional hazard which could affect your equipment or its performance. The warning symbol (lightning bolt) alerts you to a "WARNING", a safety hazard which could affect you and the equipment Installation Proper heater selection and installation will result in efficient heat transfer, safe operation, and long heater life. 1. Megohm precheck During shipping and/or storage, the possibility of moisture absorption by the insulation material within the element is possible. To ensure proper megohm values a minimum 500 VDC megohm meter (Megger) should be used to ensure that the megohm reading between the heater terminal and the heater sheath is more than 10 megohms when the unit is at room temperature. If several units are interconnected, the megohm of the heater is obtained by taking the reading and dividing by the number of interconnected elements. This reading should be greater than 10 megohms. If a low megohm value exists, two alternative methods can be used to remedy the situation. The best method is to remove all terminal hardware including thermostat if provided, and bake out the heater at no higher than 250 F (120 C) overnight or until an acceptable reading is reached. The second method is to energize the unit at low voltage in air until the megohm is at an acceptable reading. Care should be taken to prevent the heater sheath from exceeding 750 F (398 C) for INCOLOY or equivalent elements, 750 F (398 C) for carbon steel elements, and 400 F (204 C) for copper elements. 2. Protection of heater elements from over temperature The use of temperature controls to regulate heating process and prevent heater over temperature is highly recommended to ensure safe heater operation. It is the users responsibility to ensure safety of the installation. WARNING: Install high temperature control protection in systems where an over temperature fault condition could present a fire hazard or other hazard. Failure to install temperature control protection where a potential hazard exists could result in damage to equipment and property, and injury to personnel.
I&M NUMBER: 316-42-10-1 Page: 2 Failure of components in a temperature control loop, such as the sensor, heater control relay or main temperature control, can result in damage to a product in process, a melt down of a heater, and / or damaging fire. To protect against this possibility, over temperature protection must be provided to interrupt or remove power from the heater circuit. A bulb and capillary thermostat is not recommended for this function since it may not respond quickly enough to adequately protect the heater. In cases where the thermostat bulb gets too hot before the system is turned off, the thermostat bulb could rupture. This could result in the thermostat remaining in the "ON" condition since there is insufficient fluid to move contacts apart. We recommend the temperature protection have appropriate third party approval, and be applied in the classification for which it was tested and approved. In order to help prevent premature failure and a potentially hazardous condition in cases where consequences of failure may be severe, use an appropriate third party approved liquid level protection device. The liquid level should be such that the entire heater is fully submerged with enough liquid above the heater to adequately dissipate heat from itself as under normal operating conditions. Consult your local authorized sales representative for specific recommendations for your application. 3. Terminal Enclosures Terminal enclosures should be selected to be compatible with the environment in which the heater will be located. It is the users responsibility to determine the need for correct rating of the electrical housing. This should be based on appropriate national and local electrical codes. Failure to use a compatible enclosure could result in heater damage and personnel danger. Standard terminal enclosures are designed for general purpose use and are rated NEMA 1. These enclosures should be applied where there will be no danger of spilled liquids, dampness, dirt, and gaseous conditions. Enclosures for wet or hazardous locations are also available, but must be installed at the factory. One 3/4" conduit entry is supplied as standard on all NEMA 1 enclosures. Location of conduit entry can be rotated by removing enclosure base from screw plug for NEMA 1 enclosures. Although enclosures are supplied over the terminals, units should be located in an area that will minimize the chance of being hit by falling or moving objects. The terminals must be protected at all times from moisture or vapor. In hazardous locations, (as defined in NFPA 70 NEC, Article 501) appropriate hazardous location electrical enclosures must be used. In order to maintain termination integrity, the terminal enclosure should be kept below 400 F (204 C). 4. Orientation / Mounting Heater orientation is important in order to ensure efficient heat transfer and safe operation. Care should be taken to allow enough room for heater expansion without compromising heat transfer. When installing the heater through the header on the tank, care should be taken to avoid bending the elements. If possible elements should be inspected to ensure that they are not touching. Failure to do so could result in shorter heater life due to higher heater temperatures. The location of an immersion heater in a process is of prime importance. To take advantage of natural convection, the unit should be located as low as possible; similar to the "X" position in Figure 1. Consideration should also be given to sludge build-up in the bottom of the tank and the need for heater removal (replacement or maintenance). Location of the heater in the sludge area will cause premature failure and lower heat transfer efficiency. The "Y" position (Figure #1) is not recommended, but can be used if properly controlled. The heated section must be immersed during operation or premature failure may result. The use of an approved
I&M NUMBER: 316-42-10-1 Page: 3 high limit device is a must for a "Y" mounting orientation together with a liquid level control where fire and/or physical damage or injury could occur. If heater is being installed in customer supplied circulation tank, a Tubular Circulation I&M manual should be obtained from the factory to ensure safe installation of heater in tank. Failure to do this could result in premature heater failure due to improper fluid flow over elements "Y" POSITION LIQUID LEVEL ALLOWANCE FOR HEATER REMOVAL "X" POSITION SLUDGE 2" MIN FEMALE PIPE COUPLING TO MATCH SCREW PLUG SIZE Figure # 1 DANGER: HAZARD OF FIRE. Electric heaters are capable of developing high temperatures so extreme care should be taken to locate heaters in safe environments. Mounting heaters in atmospheres containing combustible gases and vapors should be avoided. According to article 501 of the NEC, the maximum surface temperature of the heater shall not exceed 80 % of the auto-ignition of the surrounding atmosphere when the heater is continuously energized. Care should also be taken to keep combustible materials far enough away to be free of the effects of high temperatures. 5. Wiring WARNING; HAZARD OF ELECTRIC SHOCK. Any installation involving electric heaters must be grounded to earth to eliminate shock hazard. Electrical wiring to the heaters must be installed in accordance with the National Electrical Code, NFPA 70, and any state and local electrical code by qualified personnel. Consult wiring diagram supplied with the unit for correct feeder or leadwire connections. If wiring diagram is not supplied, the factory should be consulted for the appropriate wiring diagram. Feeder wire should be properly selected based on amperage, electrical power rating, ambient temperature, and type of environment. Feeder wire should also be housed in either rigid or flexible conduit which carries the same classification as the heater enclosure. It is the users responsibility to properly size and install feeder wire. Feeder wire line connections are to be made directly to stud terminals. Use a ring terminal (T&B, Amp, etc.) for making these connections. It is essential that these connections be tight. For 1" and 1¼" NPT the 90º connector should be held with a pair of pliers while the screw is tightened against the ring terminal. For 2" to 2½" NPT units the bottom nut should be supported while applying a maximum torque of 20 in-lbs to the top nut. Ground connection (color coded "green") is supplied inside the housing for ground wire. Line voltage must be equal to or less than rating stamped on the heater assembly. Some units are supplied as dual voltage. Example: 240V / 480V, check wiring diagram supplied with the unit to make sure which scheme was used. In most cases (unless specified by customer) units are wired for the higher voltage.
I&M NUMBER: 316-42-10-1 Page: 4 Thermostats can be supplied with Screw Plug heaters. Consult the wiring diagram supplied with the heater for the suggested wiring of thermostats. For safe operation of thermostats, consult Installation and Maintenance manual for thermostats that is attached. Thermostats should not be used as an "OFF" device; the use of a disconnect switch or circuit breaker is recommended. The disconnect switch will allow isolation of the heater when maintenance of the heater is required. Start Up Before energizing the heater the following items should have been checked with the heater power disconnected: 1. Immersed section of heater is completely covered by liquid 2. Electrical termination is tight and wiring is per wiring diagram supplied with heater 3. Proper disconnecting means and fusing have been installed 4. The voltage rating of the heater is the same as that being applied 5. Megohm is within acceptable limits 6. Proper temperature controls and safety limiting devices are in place 7. Heater is securely installed in tank header and no leaks are visible After applying power to the heater make sure that the system is being controlled properly before leaving it to run unattended. Failure to do this could result in overheating resulting in personnel danger and fire. Troubleshooting PROBLEM No power available to heater Fuses blowing Not enough power Fluid not heating to desired temperature High limit tripping / alarm Cause / Correction Check disconnect switch to ensure it is in the "ON" position and that fuses are not blown. Replace fuses if they are blown Check heater electrical rating. Applied voltage may be wrong Check fuse rating. Fuses should be at least 25% more than full load amperage. Disconnect heater power source. Check the heater resistance to ground. This should be no less than 1 Megohm. Refer to Megohm checking. Check line voltage to ensure it is within specification Check full line current if voltage is correct. If line current is lower, the heater may be wired wrong or has open elements Not enough Kw or incorrect voltage being applied Too much heat loss, higher wattage heater may be required Not enough fluid flow Too much Kw Line voltage higher than designed / allowable! Preventative Maintenance CAUTION: HAZARD OF ELECTRIC SHOCK. TURN ALL POWER TO HEATER OFF, USE APPROPRIATE DISCONNECT LOCKOUTS AND ALLOW SYSTEM/HEATER TO COOL BEFORE PERFORMING ANY MAINTENANCE
I&M NUMBER: 316-42-10-1 Page: 5 Check line connections to make sure they are tight, free of oxide build-up, and that no dust or dirt build-up is present. Retighten to 20 in-lbs as necessary. Check enclosure (inside) for rust, dirt or dust. Remove rust if present, with steel wool (or equal) and thoroughly blow clean with dry, oil-free air. If enclosure is moisture resistant, check condition of cover gasket. A replacement can be obtained from the factory. Liquid immersed units should be removed from tank and checked periodically for scale build-up. Clean as required. Scale can cause high sheath temperature and result in inefficiency and shortened life. Thermal cycling may cause sealed joints to relax causing a leak. Tightening of heater plug should stop leak. Replacement Parts Reference the Screw Plug heater part number on the nameplate when ordering replacement parts. Recommended spare parts would be : a Screw Plug Heater and thermostat (if supplied). Contact your local Watlow distributor for ordering replacement parts. Check the Yellow Pages under "Electrical Heating Elements" in the largest industrial area nearest you. Warranty Watlow warrants its products against defects in material and workmanship for 12 months from the date of delivery for custom products and 18 months for stock products providing such products are properly applied, used and maintained. Watlow does not warrant any product against damage from corrosion, contamination, misapplication, improper specification or operating conditions beyond our control. The terms of this warranty are the exclusive terms available to any person. No person has authority to bind the Company to representation or warranty other than this warranty. Watlow is not liable for incidental or consequential damages resulting from use of the product whether a claim for such damages is based upon warranty, contract, negligence or other fault. Should any product fail under these warranty conditions it will be repaired or replaced at no charge. Advanced authorization must be obtained within 30 days of failure. Return Policy 1. Call Watlow Industries at 573-221-2816, for a Return Material Authorization (RMA) number before returning any item for repair or replacement. The following information is needed to process a returned heater expeditiously: Customer name Customer account number Contact Name Phone Number Part number P.O. number Quantity Reason for return Application information MSDS sheet of material(s) that came in contact with heater, if used. 2. Prior approval and an RMA number is needed when returning any unused product for credit. Make sure the RMA number is on the outside of the carton, and on all paperwork. Return all material Freight Prepaid basis.
I&M NUMBER: 316-42-10-1 Page: 6 3. Stock heaters and accessories which have not been used or modified can be returned to the plant for a 20% restocking charge. Modified stock units can only be returned, if they are not permanently modified, for a minimum 30% restocking charge. 4. All stock and modified stock must have a date code no later than 2 years from the date of shipment. REVISIONS LEVEL DESCRIPTION INITIALS DATE 1.00 Created Document 2.00 3.00 ADDED Date:6/11/2008 TO HEADER PER ECO HAN2838 TBR 06-11-08